Phosphate-free carboxylate-sulfate detergents

ABSTRACT

Detergent-active materials having low fish toxicity suitable for heavy duty laundering in the absence of builders comprising sulfated glycol or polyglycol half esters of alkyl or alkenyl succinic acids, or water-soluble salts thereof, wherein the alkyl or alkenyl group contains from about 14 to about 22 carbon atoms, the glycol moiety of the ester contains from 1 to 4 units of 2 to 4 carbon atoms, and the sulfate group is terminally attached to the glycol or polyglycol chain.

United States Patent [191 Danzik et al.

[451 Oct. 22, 1974 PHOSPHATE-FREE CARBOXYLATE-SULFATE DETERGENTS [75] Inventors: Mitchell Danzik, Pinole', Ralph House, El Sobrante, both of Calif,

[73] Assignee: Chevron Research Company, San Francisco, Calif.

[22] Filed: June 5, 1972 [21] Appl. No.: 259,924

[52] US. Cl 260/458, 252/551, 260/346.8 [51] Int. Cl. C07c 141/02, C07c 141/10 [58] Field of Search 260/458 [56] References Cited UNITED STATES PATENTS 2,121,616 6/1938 Werntz 260/458 X 2,630,449 3/1953 Blake 260/458 2,637,740 5/1953 Kosmin 260/458 3,376,333 4/1968 Ernst et al. 260/458 11/1968 Blood et al. 260/458 9/1972 Emmons et a1. 260/458 X Primary Examinerl-loward T. Mars Assistant Examiner-Norman P. Morganstern Attorney, Agent, or FirmG. F. Magdeburger; John Stoner, Jr.; J. T. Brooks 5 7 ABSTRACT 3 Claims, N0 Drawings DETERGENTS BACKGROUND OF THE INVENTION This application is directed to detergent active materials which may be incorporated into detergent formulations which are capable of being used for heavy duty laundering without the presence of either eutrophication-causing or highly alkaline materials which are harmful to human tissue. In addition, these detergent active materials possess other virtues, the combination of which is unique in the detergent area. Thus the compounds are both aerobically and microaerophilically biodegradable and possess low (exceptionally low with certain species of the compounds) fish toxicity properties.

As is well known, in the US. accelerated concern for the protection of the environment has resulted in efforts by the concerned branches of Government and the detergent industry to eliminate phosphate builders from detergent compositions because of the fear of suspected eutrophication believed to be caused by the phosphates in the currently used detergent formulations. The precipitous introduction and marketing of many hurriedly formulated phosphatefree compositions has, however, raised the spectre of .thecure being possibly worse than the illness due to the caustic nature of many of the formulations. The necessity of including some builder in the formulations as a replacement for the phosphates in order to achieve sufficient detergency has resulted in these formulations being compounded with such materials as meta-silicates and carbonates making the danger of skin, eye, and mucous membrane damage to persons who use the formulations a substantialone. Thus the Federal government has required that several of the new detergent formulations be labeled as hazardous substances and the Surgeon General of the US. has recently recommended that housewives continue to use phosphate-containing detergents for the present as being the lesser of evils.

In addition to the corrosive properties of many of the new detergent formulations, despite claims to the contrary, many of them have not proved to be effective replacements for conventional heavy duty detergents in terms of their ability to remove soil from fabrics and provide clean-appearing clothes, etc.

An additional problem with most conventional detergents and which exists as well with most of the newly introduced non-phosphate detergent compositions is the fact that while they may be aerobically biodegradable withsecondary disposal plants, they are not easily degradable under "microaerophilic" conditions such as are encountered in areas where septic tanks and cesspools provide the means of sewage disposal. This results in substantial quantities of undegraded surfaceactive materials being discharged into water sources and has resulted in certain areas in Government bans on all laundering agents except for soap.

There exists, therefore, a pressing need for detergenactive materials which may be compounded without phosphate builders and without caustic builders, which are biodegradable and are degradable under conditions encountered in septic tanks and cesspools and which will have minimal effect on marine organisms if discharged by design or accident into rivers and lakes, etc.

Thus the detergent actives should not exhibit high toxicity to fish, etc.

PRIOR ART.

US. Pat. No. 3,086,043 discloses as surface active materials compounds of the formula R-CH-CHiC 0 o CHCH2(0 CHCH:),SO3Z

0 on R R" in which R is alkenyl of 8 to 20 carbons (preferably branched), R is lower alkyl of l to 4 carbon atoms or hydrogen, x is 0 to 3, and Z is a salt forming cation. The compounds are formed by reacting a hydroxycontaining sulfonate such as sodium isethionate with alkenyl succinic anhydride.

SUMMARY OF THE INVENTION tergent actives are sulfated glycol or polyglycol half esters of alkyl or alkenyl succinic acids or water-soluble salts thereof, wherein the alkyl or alkenyl group contains from about 14 to about 22 carbon atoms and the glycol moiety of the ester contains from I to 4 units of 2 to 4 carbon atoms and the sulfate group is terminally attached to the glycol or polyglycol chain. The preferred glycol units contain two carbon atoms.

While the compound disclosed above have good detergency and low fish toxicity levels consonant with most of the available detergents such as linear alkylbenzene sufonate, a preferred embodiment of the invention having, along with excellent detergency, surprisingly low fish toxicity levels is represented by the class of compounds of the following formula:

in which R and R are substantially linear saturated or unsaturated aliphatic groups of 2 to 19 carbon atoms,

R is'alkylene of 2 to 4 carbon atoms, u, v, x and y are 0 or 1, z is an integer l to 4, M is lI-Ior a water-soluble salt-forming cation, the sum of the carbon atoms in R and R is from about 13 to 21 carbon atoms, the sum of unsaturated sites in R and R is O to l, the sum of u and v is l, the sum of): and y'is l, and the sum ofu and x is l.

Thus the preferred compounds are preferably derived from hydrocarbyl succinic anhydrides wherein the attachment of the succinic moiety to the hydrocarbyl group is at carbon atoms other than the l and 2 carbon atoms of the hydrocarbyl chain. Such attachment as used in this application is defined as central attachment. Bonding at carbon atoms 1 and 2 of the hydrocarbyl group is defined as end attachment.

In an additional preferred embodiment z is an integer of l to 3, preferably 1 to 2, most preferably 2, and R, is ethylene. It is further preferred that the sum of carbon atoms in R, and R is from to l7. Thus, the preferred materials are sulfate salts of half esters produced by reacting ethylene glycol or diethylene glycol with an alkyl or alkenyl succinic anhydride having 16 to 18 carbon atoms in the side chain. The diethylene glycol derivative is most preferred as is the alkyl derivative.

The hydrocarbyl radicals illustrated in the formula by R,R Cl-I- include such groups as tetradecyl, pentadecyl, hexadecyl, heneicosyl, docosyl, tetradecenyl, pentadecenyl, hexade'cenyl, heneicosenyl and docosenyl.

Typical compounds illustrating R,, R and R are listed as follows:

DESCRIPTION OF THE PREFERRED EMBODIMENTS The salt-forming cation M may be any of numerous materials such as alkali metal, alkaline earth metal, ammonium, or various organic cations, Examples of suitable organic cations include nitrogen-containing organic cations such as diethanolammonium and triethanolammonium cations. The alkali metal cations are preferred, and sodium ions are particularly preferred.

The alkyl and alkenyl groups which are attached to the succinic moiety may be branched or linear, although the substantially linear materials are preferred. By substantially linear is meant that the presence of a random methyl group, for example. somewhere on the chain will not be detrimental to their ability to be degraded. The preferred alkyl groups thus include the linear alkyl from tetradecyl to docosyl and the alkenyl groups will likewise be the linear materials from tetradecenyl to docosenyl.

The succinic anhydride precursors are preferably derived by the alkylation of maleic anhydride with a monooleiin to form alkenyl succinic anhydride followed in the case of the alkyl substituted materials by hydrogenation. The olefins may be derived from any source, examples, being those derived from the cracking of waxes (alpha olefins) or those derived by dehydrogenation or halogenation-dehydrohalogenation of appropriate paraffin fractions. From a commercial standpoint olefins derived by various dehydrogenation processes are preferred. 1

The reaction of olefin with maleic anhydride is performed as conventionally described in the art by contacting the anhydride with at least an equimolar amount; preferably an excess of olefin, usually at elevated temperatures, to form the desired anhydride.

The alkenyl materials maybe converted to alkyl succinic anhydrides by conventional hydrogenation techniques. Alternatively and preferably, the hydrogenation is carried out with the half ester. Hydrogenation may thus be carried out in the presence of conventional catalysts such as platinum, platinum on inert supports, palladium, etc. I

The alkenyl or alkyl succinic anhydride is reacted with an appropriate quantity of a lower glycol or lower polyglycol to yield the half ester. An approximately stoichiometric amount of the glycol or polyglycol will cleave the anhydride ring to form the desired compound having a free carboxyl group and a hydroxyl group on the glycol or polyglycol portion of the molecule. The use of anexcess of the glycol is preferred.

Sulfation of the glycol substituted half ester to produce the acid precursor of the compound is accomplished by any appropriate sulfation method, such as with oleum, sulfuric acid, or chlorosulfonic acid.

The mixed carboxylic, sulfuric acid produced is reacted with an appropriate base in order to give the de- (RiRaCH in which Y is H or a water-soluble salt-forming cation, 2 is 1 to 4, R, and R are substantially linear saturated or unsaturated, unsubstituted aliphatic groups of 2 to 19 carbon atoms, R, is alkylene of 2 to 4 carbon atoms, u, v, x and y are 0 or I, the sum of the carbon atoms in R, and R is from 13 to 21 carbon atoms, the sum of the unsaturated sites in R, and R is 0 to l, the sum of u and v is l, the sum ofx and y is l, and the sum ofu and x is 1. In the preferred precursor the sum of the carbon atoms in R, and R is 15-17, and p is 1 to 2, preferably 2; and R, and R are alkyl.

The following examples illustrate the preparation of the detergent active materials of this invention.

EXAMPLE I Preparation of Octadecenyl Succinic Anhydride 9.08 kg. (36.0 moles) of isomerized linear octadecene and 1.96 kg. (20.0 moles) of maleic anhydride were charged to a pressure vessel. The stirred mixture was heated under 30 psi of nitrogen for 6 hours at 230C. After the mixture cooled, it was transferred to a distillation apparatus and distilled, boiling point 430450F. at 0.1-0.2 mm/Hg. A 93 percent yield of octadecenyl succinic anhydride was I obtained. The product had the following isomer distribution as determined by vapor phase chromatography:

lsomcr Percent Z-attachmcnt B-attachment 4-attachment S-attachment 6.7.8,9-attachment This represents a product having 95.5 percent central. attachment.

EXAMPLE 2 Hydrogenation of Octadecenyl Succinic Anhydride g. (0.057 moles) of octadecenyl succinic anhydride, 114 g. of n-hexane and l g. of 5 percent palladium on carbon were charged to a pressure vessel. The mixture was stirred and heated to 50C. The initial hydrogen pressure was 60 psi. When the pressure dropped to 50-50 psi, the system was repressured to 60 psi. This process was repeated until the hydrogen uptake essentially ceased. The mixture was filtered and the hexane was evaporated. 19.7 g. (98.5 percent yield) of crude octadecyl succinic anhydride was recovered.

EXAMPLE 3 Preparation of Diethylene Glycol Half Ester of Octadecenyl Succinic Acid 238.0 g. of diethylene glycol (2.25 moles) and 26.3 g. of a linear octadecenyl succinic anhydride (0.0747 mole) prepared as in Example 1 was placed in a vessel and stirred and heated rapidly to l50-160C. The solution was maintained at that temperature for one hour,

EXAMPLE 4 Preparation of Ethylene Glycol Half Ester of Octadecenyl Succinic Anhydride The procedure of Example 3 was repeated with the exception that 177 g. of ethylene glycol (2.86 moles) and 25.0 g. of octadecenyl succinic anhydride (0.0714 mole) were employed. The yield of product was 95 percent.

EXAMPLE 5 Hydrogenation of Diethylene Glycol Half Ester of Octadecenyl Succinic Anhydride 9.12 g. (0.02 mole) of a diethylene glycol half ester of octadecenyl succinic acid was dissolved in 42 ml. of n-hexane in a hydrogenation vessel. 1 g. of 5 percent palladium on carbon was added. The mixture was magnetically stirred and heated in a 50C. Water bath. The initial hydrogen'pressure was 60 psi. When the pressure dropped to 3040 psi. the system was repressured to 60 psi. This process was repeated until the theoretical hydrogen uptake was obtained. The mixture was'then filtered and the hexane was evaporated. 14.9 g. (99 percent yield) of diethylene glycol half ester of octadecyl succinic acid was recovered. Infrared and nuclear magnetic resonance analysis were consistent with the as signed structure and showed that the product was completely saturated.

EXAMPLE 6 chlorosulfonic acid was added dropwide at a rapid rate.

The temperature of the reaction mixture was kept at 10-l 5C. during the addition of the acid. When all of the acid was added, the cooling bath was removed, and the solution was allowed to warm to room temperature over a period of 20-30 minutes.

Sufficient 0.5 N NaOH was added to about ml of water to bring the pH to 1 1-12.The solution was cooled to 5l0C., and the pH was maintained between 8 and 12 by alternate addition of the acid-containing ether solution and 0.5 N NaOH. At a final pH of 8.5, the mixture was partially evaporated .to remove ether. The remaining solution was diluted to a known volume. An aliquot was taken for a Hyamine titration, andthe amount of active sulfate was determined. The yield of disodium salt of sulfated diethylene glycol half ester of octadecyl succinic acid was 87 percent.

EXAMPLE 7 Sulfation of an Ethylene Glycol Half Ester. of Octadecenyl Succinic Acid The procedure of Example 6 was repeated with the exception that 2.20 g. (0.00533 moles) of an ethylene glycol half ester of octadecenyl succinic acid and 5.03 g. of chlorosulfonic acid (0.043 moles) were used.

A'hyamine titration of an aliquot from a known volume of solution which contained the produce gave a 104 percent yield of anionic active.

Acid hydrolysis of this crude product indicated that the yield of the disodium salt of sulfated half ester of ethylene glycol and'octadecenyl succinic acid was 92 percent, and the yield of a sulfonated-sulfated byproduct was 6 percent.

Other compounds were prepared by essentially the same procedures as above. These are listed in Table I.

TABLE 1 DlSODlUM SALTS OF EX. SULFATED DlETHYLENE vYIELD CENTRAL NO. GLYCOL HALF-ESTERS OF: ATTACH. ('4) 8 Hexadecyl 93 95 9 Hexadecyl 94 0 10 Heptadccyl 89 91 l l Nonadccyl 86 94 12 Pentadecenyl l3 Hcxadecenyl 84 95 14 Hexadeccnyl 72 0 15 Hcptadecenyl 86 91 16 octadecenyl 95 17 Nonadcccnyl 73 94 18 Eicosenyl 83 19 Cut-Cm (saturatedi 89 94 20 Cut-C (unsaturated 93 21 -C (unsaturated) 75 (Est.)

22 -C (unsaturatedf 93 23 (I -C (unsaturated)" 93 24 Hcxadecyl 95 25 Hcptadecyl 91 26 Ocatdecyl 91 95 Ocatdecyl TABLE l-Continued DlSODlUM SALTS OF A blend of approximately equal amounts of eaich'isomcr.

A blend having a ratio 01 30:40:30 for isomers of increasing molecular weight. respectively.

A blend having a ratio of26:29:27:l3 for isomers ofincrcasing molecular weight. respectively.

EXAMPLE 37 Drying of Disodium Salt of the Half Ester of C -C Alkyl Succinic Acid A portion of disodium salt of the half ester ofC C alkyl succinic acid was dried on a small scale drum dryer under 35 lbs. of steam absolute (about 125C.) The product was crushed and screened to give a prod uct which was a free-flowing white powder when dry.

The sulfation products contain varying amounts of by-products in the range of about 1 to 20 percent. The alkenyl derivatives have the greater quantity of byproducts, about 10 to percent, whereas the alkyl derivatives have lesser amounts, about 1 to 10 percent These by-products may be removed by various purification processes such as extraction,chromatography, etc., but in the present examples they were left in the products because these by-products will normally be present in commercial materials made in accordance with this invention. Consequently, detergency and toxicity measurements reported herein are representative of potential commercial products. Each product was analyzed fordetergent active material by the method of House and Darragh, Anal. Chem., 26, 1492 (1954).- Test samples were prepared for fish toxicity measurements and for detergency effectiveness using the previously determined surface active values for determining test concentrations.

Detergency of the compounds of the present invention is demonstrated by a miniature Terg-O-Tometer test. In this test the effectiveness of the detergents is measured by their ability to remove natural sebum soil from cotton cloth. By this method, small swatches of cloth, soiled by rubbing over face and neck, are washed with test solutions of detergents in a miniature laboratory washer. The washer employed is so constructed that two standard formulations and two test formulations can be used to wash different parts of the same soiled swatch. This arrangement ensures that all formulations are working on identical soil. The quantity of soil removed by this washing procedure is determined by measuring the reflectances of the new cloth, the soiled cloth, and the washed cloth, the results being expressed as percent soil removal. Because of variations in degree and type of soiling, in water and in cloth, and other unknown variables, the art has developed the method of using relative detergency ratings for comparing detergent effectiveness.

The relative detergency ratings are obtained by comparing and correlating the percent soil removal results from solutions containing the detergents being tested with the results from two defined standard solutions. The two standard solutions are selected to represent a detergent system exhibiting relatively high detersive characteristics and a system exhibiting relatively low detersive characteristics. The systems are assigned detergency ratings of 6.3 and 2.2, respectively.

By washing aradise?EHEEiiE'ith with the standardized solutions, as well as with two test solutions, the results can be accurately correlated. The two standard solutions are identical in formulation but are employed at different hardnesses.

Standard Solution Formulation The standard exhibiting high detersive characteristics (Control B) is prepared by dissolving the above formulation 1.0 g.) in one liter of 50 ppm hard water (calculated as two-thirds calciumparbonate and one-third .magnesium carbonate). The low .detersive standard :(Control A) contained the formulation (1.0 g.) dissolved in one liter of 180 ppm water (same basis).

A further refinement in the determination of relative detergency ratings was developed. In this method, in-

stead of employing two standard formulations, one of the formulations used as one of the four test solutions had a known relative detergency rating. (RDR) which had been determined by the above formula. Relative detergency ratings of the other three formulations were then determined by comparing the percent soil removal (SR) of these formulations with that of the known formulation.

water, and sufficient sodium sulfate to make percent. The LAS comparison formulations were prepared in the same way except that in Test 1 20 percent of LAS and 35' percent of sodium tripolyphosphate were used. The formulations were tested at. a concentration in water of 0.10 and 0.15 weight percent. The test results were obtained at a pH of 9.5.

TABLE 11 DETERGENT EFFECTIVENESS RELATIVE DETERGENCY RATINGS TEST AT 0.1% (Wt.) Conc. At 0.15% (WL) Conc. No. COMPOUND TESTED 50 ppm 100 ppm 180 ppm 50 ppm 100 ppm 180'ppm l LAS with phosphate 5.8 3.9 1.7 6.3 6.2 4.1 2 LAS without phosphate 2.6 1.3 0.0 3.9 2.4 0.9 3 Product of Ex. No. 14 6.1 5.0 4 do. 13 4.7 4.4 5 do. 9 6.3 5.4 6 do. 5.4 4.7 7 do. 16 5.3 4.7 8 do. 17 5.4 4.6 9 do. 18 5.] 4.8 10 do. 12 4.2 4.1 11 do. 6 5.6 4.9 12 do. 19 5.3 4.8 3 9 5 8 5 4 4.9 13 do 5.0 4.8 14 do 22 5.3 4.9 15 do 30 5.5 5.0 16 do 29 5.6 4.6 17 do 4.9 4.7 is do 24 3.6 4.4 19 do. 26 5.4 4.8 20 Product of Ex. No. 27 5.6 5.1 21 do. 28 5.6 5.1 22 d0. 34 5.4 4.8 23 do. 35 5.2 4.7

As can be seen from these data, the compositions of this invention are highly effective as heavy duty laundering agents. Their effectiveness is comparable to conventional LAS with phosphate and surprisingly more effective than LAS without phosphate builders.

In order to determine the tolerance of fish for the detergent active compounds of this invention the following routine bioassay method was employed: Standard Methods for the Examination of Water and Waste Wa ter, American Public Health Association, pages 458-471, 1 1th Edition (1960). The test is performed as follows: For each test concentration a S-gallon jar containing 10 liters of tap water dechlorinated by air blowing was prepared. The test surfactant is added and 10 sticklebacks (Gasterosteidae) are transferred from a fresh water holding tank to the jar. Dead fish are counted and removed at 6 hours, 24 hours, 48 hours,

with more than 50 percent survival and the lowest cons rio s! h. 5.5 tha 50 pi ssnts d It was found in these tests that those compounds having central attachment of the succinic ester portion of the molecule to the hydrocarbyl chain were surpris-- ingly less toxic than the compounds having end chain attachment. Table 111 contains data comparing the toxicity of compounds having central and end chain attachments.

Data 555' a representative atlases of other com 40 pounds of this invention are set forth in the following table. These data are compared with the TL values for LAS and other conventional detergents.

TABLE 111 F1S1-1 TOLERANCE TEST v CENTRAL END CHAIN TL NO. COMPOUND TESTED ATTACH.(%) ATTACH.(%) PM) 1 Product of Ex. No. 28 0 100 0.3 2 do. 27 25 0.8 3 do. 26 V 5 1.8 4 do. 9 0 2.2 5 do. 8 95 5 20.0 6 do. 14 0 100 5.3 7 do. 13 95 r s 20 TABIETV FISH TOLERANCE NUMBER OF TEST CARBON ATDMS 1N TL... NO. COMPOUND TESTED HYDROCAlRBYL (PPM) CHAIN 8 LAS 10-13 3.2 9 LAS 11-14 1.6 10 Tallow alcohol sulfate 18 1.3 l l Ethoxylated primary l415 3.]

alcohol" 12 Product of Ex. No. 10 5-6 1 1 TABLE IV -Continued FISH TOLERANCE All non-commercial compounds have about 91-95% central attachment, except test No. 25 which has 8361 central attachment. Commercial product. Run in ppm hardness (otherwise precipitates with hardness).

These data show that the TL values for most of the compounds of this invention, particularly those having internal attachment are surprisingly higher than the linear alky1benzene sulfonate.

The degree of degradation under conditions such as are encountered in cesspools and septic tanks for the compounds of this invention were determined by tests set forth in Microaerophilic Biodegradation of Tallow-Based Anionic Detergents in River Water," E. W. Mauer, T. C. Crodon, and A. J. Stirton, The Utilization Res. Dev. Div., ARS, USDA, Philadelphia, Pennsylvania, JAOCS, Volume 48, Page 163 (1971 The microaerophilic test procedure described in this article was employed with the exception that a bacterial seed (l0 percent of filtered primary sewage anaerobic digester mix) was employed, the test was operated at room tem-.

perature and, in contrast to the results obtained by the authors, a small amount of degradatior was observed in each case for linear alky1benzene sulfonate.

Data in the following table show the degradation performance of the compounds of this invention in this test. The amount of surfactant in percent remaining after 2, 3, 5 and 6 days determined by standard methylene blue analysis is set forth.

TABLE V agents, foam boosters, and certain organic and inorganic alkali metal and alkaline earth metal salts such as inorganic sulfates, carbonates, or borates. Also non phosphate builders may be included in the composition. Also small quantities of phosphate builders may be included in the compositions, although, of course,

they are not necessary for effective detergency.

While the character of this invention has been described in detail with numerous examples, this has been done by way of illustration only and without limitation of the invention. It will be apparent to those skilled in the art that modifications and variations of the illustrative examples may be made in the practice of the invention within the scope of the following claims.

We claim: 1

1. Surface active compounds of the formula MICROAEROPHILIC TEST Percent Active Remainin After Ela sed Time Compound 2 Days 35 Days 3 Days 6 Days LAS 84 75 44 41 Product of Ex. No. 19 23- 13 7 7 The sulfate-carboxylates of this invention may be employedin combination with other detergent active materials such as linear alkyl and alkenyl'disulfates and disulfonates, straight chain primary alcohol sulfates, LAS, olefin sulfonates and soap. in employing the detergent active materials of this invention in detergent compositions, they may be formulated with additional compatible ingredients being optionally incorporated to enhance the properties of the formulations. Such materials mayinclude but are not limited to anticorrosion, antiredeposition, bleaching and sequestering of 3 to 19 carbon atoms, 14, v, x and y are 0 or 1, M is an alkali metal, alkaline earth metal, or ammonium cation, the sum of the carbon atoms in R and R is 13 to 21, the sum ofu'and v is l, the sum ofx andy is l,and the sum ofu and 3c is 1.

2. Compounds of claim 1 in which M is an alkali metal cation.

3. The compound of claim 2 in which M is Na and the sum of the carbon atoms in R, and R is 16. 

1. SURFACE ACTIVE COMPOUNDS OF THE FORMULA
 2. Compounds of claim 1 in which M is an alkali metal cation.
 3. The compound of claim 2 in which M is Na and the sum of the carbon atoms in R1 and R2 is
 16. 